Green’s Dictionary of Slang

(orig. drugs) depressed, esp. after a period of elation.

1941		Warner, Junker & al. Color & Human Nature 260: When I learned that they took me to the hospital in the patrol wagon, I sure was brought down.
1941		A. Gurney Bluey & Curley [synd. cartoon strip] .
c.1951		N. Algren ‘Watch Out for Daddy’ in Entrapment (2009) 125: I scarcely could blame him for feeling brought down.
1958		G. Lea Somewhere There’s Music 162: I figured you’d be brought down about that.
1961		T. Taylor Baron’s Court All Change (2011) 69: [H]e was always brought down, and never failed to tell you so.
1967		Oz 4 25: They were very brought down by the war scenes here.
1972		Zigzag Aug. n.p.: That tour was blown out and we were very brought down.
1983		K. Hudson Dict. of Teenage Revolution 29: Brought down. Depressed.
2002		Observer Mag. 27 Oct. 11: It was alcohol that really brought him down.